Quantitative Aptitude - Arithmetic Ability Questions

If a - b = -1 and ab = 6, then what is the value of a3- b3?

The line passing through (-2,5) and (6,b) is perpendicular to the line 20x + 5y = 3. Find b?

A man covers a total distance of 100 km on bicycle. For the first 2 hours, the speed was 20 km/hr and for the rest of the journey, it came down to 10 km/hr. The average speed will be

Atul can do a piece of work in 18 days, Aaravya is 50% more efficient than Atul. How much more time does Atul take than Aaravya to do the same piece of work?

The ratio of sand to gravel in a mixture is 17:8 while that between gravel and cement is 6:17. What is the ratio of sand to cement in the mixture?

An 80 litre mixture of water and acid contains 20% acid. How much acid should be added to make the acid 60% in the new mixture?

In the given figure, AB, AE, EF, FG and GB are semicircles. AB = 56 cm and AE = EF = FG = GB. What is the area (in sq.cm) of the shaded region?

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.